In many methods of analysis, including immunoassays and DNA detections, a solid phase needs to be separated from a liquid phase, and subsequently washed. The last separation step in the washing process is usually followed by conveyance of the sample to a processing station (for example, an incubator) where reagent solutions are added. In the conventional method of addition, solutions are pipetted into the middle of the reagent vessel through the tip of a pipette. Reagent and solid phase must be well mixed if subsequent chemical reaction is to proceed quickly and efficiently (for example, during incubation). To thoroughly suspend the solid phase, prior art processes employ a shaking operation. Either the reaction container or the entire processing station are shaken. Such required equipment increases complexity, and thus increases the cost and total bulk of the plant. The shaking operation also disadvantageously prolongs total processing time.
The subject invention fulfills a long felt need for an apparatus and method which suspend particles without requiring an additional suspension device or shaking operation.